Due to recent advance of electronics, and information and communication technology, a mobile handset for operating in mobile telephone system including PHS (Personal Handyphone System), PDA (Personal Digital Assistant) and other mobile information communication apparatuses, which send or receive data by wireless communication, have become multifunctional, so that it comes normally equipped with a web browsing function, as well as with an e-mail sending and receiving function, which enables to acquire document files described by markup language and their linked files from a web server connected to the Internet, and to display texts and images in a proper layout on its own attached display means which usually is a liquid crystal display panel.
Hereinafter, “a mobile handset for operating in mobile telephone system including PHS” is referred as “a mobile telephone unit”, and “a document file described by markup language” is referred as “a markup document file”.
Many mobile telephone units also have a game function, by which one can enjoy a change of image displayed on their own attached display by manually operating its own attached key operating part to activate a program, which is downloaded from a web site and is stored in a storage means such as a flash memory, and to input required data. Moreover, some mobile telephone units have a television tuner function to receive a wireless signal of television broadcast and to display a picture of a TV program on their own attached display.
Hereinafter, “a wireless signal of television broadcast” is referred as “a TV signal” in the followings.
Especially since a digital terrestrial broadcast is scheduled to start, it is expected that merging of a digital television tuner function and a web browsing function in a mobile telephone unit enable to provide a user of the mobile telephone unit with a service taking both advantages of a concurrent broadcast and the Internet with personal and interactive characteristics.
Under these circumstances, a display function of image including a text and a picture is thought to be more important in a mobile information communication apparatus centering on a mobile telephone unit. However, a mobile telephone unit and other mobile information communication apparatuses cannot have large size display means because of a constraint of portability. Thus, in the case of a mobile telephone unit, screen's size is around 2.5″ at maximum and screen's resolution is QVGA (Quarter Video Graphics Array). Note that because a mobile telephone unit is usually used in a vertically long configuration, QVGA means “horizontal×vertical=240×320 pixels”.
When a mobile information communication apparatus receives a long e-mail of which a sentence extends in many lines and does not fall once in its own attached display screen due to a screen constrain, an e-mail receiver using the apparatus has to roll down the screen and cannot understand the meanings of the text smoothly as a result. On the other hand, an e-mail sender has to make his e-mail, which is addressed to a mobile information communication apparatus, short enough considering such screen constraint of a receiver, even though the sender uses a desktop or a notebook personal computer system of which display screen is large enough to display long text without any problem.
Hereinafter, “a desktop or a notebook personal computer system” is referred as “a PC”.
Moreover, it is more constrained to browse a web page by using a mobile information communication apparatus than to read e-mail by using it. A web page intended to be browsed with a PC is usually composed of document files described by HTML (Hyper Text Markup Language) and their linked files.
Hereinafter, “a web page intended to be browsed with a PC” is referred as “a web page for PC”, and “a document file described by HTML” is referred as “an HTML file”.
However, it is impossible to properly browse a web page described by full-spec HTML by using an average mobile telephone unit partly because the screen's size and resolution of its own attached display means is short. It is possible only to browse a web page of so called “mobile site”, which is described by a markup language specialized for a mobile information communication apparatus such as CHTML (Compact HTML), HDML (Handheld Device Markup Language) and WML (Wireless Markup Language). Thus, a web page composed of HTML files and their linked image files with high resolution is scarcely able to be displayed properly, and a mobile telephone unit is sometimes rejected by an administrator to access a web site including web page with frame layout, where a screen is divided into some frames with separate URL (Uniform Resource Locator).
Recently, mobile telephone units with “a full browser function” or “a PC site view function”, with which a web page for PC can be browsed are on sale, but in many cases the same screen image as that is displayed on a PC screen and is originally intended by a web page creator is not displayed, since particular kind of rendering mode is taken such that image size is reduced to fit a screen's resolution of a mobile telephone unit that is 240 pixels in the case of vertically long QVGA, text moves to next line according to screen width, or each frame is displayed in a separate page in the case of a frame layout web page.
Some mobile telephone unit takes such rendering mode as to display a web page for PC in similar layout as displayed in a PC screen, but a web page for PC is created to target VGA screen (horizontal×vertical=640×480 pixels) at lowest, so it is difficult to understand the whole meaning of a web page because a whole page cannot be browsed without a frequent horizontal scrolling.
Hereinbefore and hereinafter, “a whole of image displayed in full screen on a display screen” is referred as” “a screen image”. Therefore, for example, when a web page composed of a document file described by markup language and its linked image files is browsed and displayed in full screen, “a screen image” is a whole of a image including all of the document text, all of the individual images corresponding to the image files, and even various menu displays of browser software.
Note that, for example, when a screen image data of VGA is inputted to a display device to meet only screen mode of XGA (eXtended Graphics Array) (horizontal×vertical=1024×768 pixels) and image is displayed only in center of the screen (or in some corner), “a screen image” means a display of the display area excluding non-display area.
By using a mobile information communication apparatus, on the other hand, one can enjoy only a relatively simple game, which can be displayed in its own attached small size display means. Since, therefore, almost all games of so-called “mobile appli” were created one or more generations ago in the field of games for a specialized game machine or a PC, they are enjoyed only for time killing in a short time.
Also, when one watches a TV program by using a mobile telephone unit of which display has a resolution of QVGA at highest, it is required to thin out pixels, because effective scanning lines required by a TV broadcast, which is equivalent to vertical resolution and is 480 in the case of an analog TV broadcast, is larger than a vertical resolution of a display means belonging to a mobile telephone unit, which is 240 pixels when a mobile telephone unit is used in a horizontally long configuration (horizontal×vertical=320×240 pixels) to watch in as large a screen as possible. Especially in the case of a digital TV broadcast, effective horizontal resolution is regulated as well as number of effective scanning lines (vertical resolution). In 480i mode, of which resolution is the lowest, horizontal resolution and vertical resolution is 720 pixels and 480 pixels respectively, and in 1080i, that is so-called “full high vision”, horizontal resolution and vertical resolution is 1920 pixels and 1080 pixels respectively. Anyway, a mobile telephone unit, of which display means has a resolution of QVGA at highest, cannot display an intrinsic image of a TV broadcast in full screen but can display only a poor image with a lower resolution than an intrinsic resolution.
Wherein “an intrinsic image of a TV broadcast” means “an image with an intrinsic resolution, which is displayed, when a TV signal is properly processed by a television receiver (TV receiver) with a sufficient tuner and display function”.
Many users of a mobile information communication apparatus possess a PC in addition to the mobile apparatus. Such a user uses a PC when he sends and receives a long e-mail, browses a web page for PC or enjoys a complex game of which graphics can be displayed only in large size screen. And a mobile information communication apparatus is utilized only for sending and receiving a short e-mail and browsing a web page of “mobile site”. In other case, only a wireless communication means of a mobile information communication apparatus, which is connected to a PC, is utilized to connect a network and data, which is acquired by using the wireless communication means, is processed only by a PC. Also, recently “AV (Audio Visual)-PC” is on sale, which has a function which enables a user to watch a TV program by using a built-in television tuner. In such a case that both of “AV-PC” and a mobile telephone unit with a television tuner are possessed, a TV program is watched by a mobile telephone unit outside or in traveling time and is watched by “AV-PC” home or in one's room.
Since, however, a PC is usually designed for a versatile use that is not restricted to sending and receiving of e-mail or browsing of web page, which can be conducted by a mobile information communication apparatus, it has a higher-performance processor, such as CPU (Central Processing Unit) or so on, than a data processing means of a mobile information communication apparatus. Moreover, it is required to prepare software, such as OS (Operating System) or so on, to activate hardware. Thus, it takes more cost to possess a PC than it does to possess a mobile telephone unit or another mobile information communication apparatus.
Therefore, it is economically irrational for major users, whose usage of a mobile information communication apparatus is restricted to sending and receiving of e-mail or browsing of web page except a telephone call, to possess a PC in order only to avoid inconvenience in reading a long e-mail or browsing a web page for PC due to short screen's size and resolution of a display means belonging to a mobile information communication apparatus.
On the other hand, although a data processing means of a mobile information communication apparatus does not have all functions as a PC's processor such as CPU, as far as a display data processing function to display an image on its own attached display means is concerned, it has a comparable function as that of a PC's processor, except that the display screen is small. Thus, it is not desirable from the viewpoint of effective resource to use both a PC and a mobile information communication apparatus as described above, because it results in low operating rate of one machine at least and it means overlapping investment to similar items.
Similar problem of “irrational overlapping investment” and “inefficient resource use” occurs in the case that a mobile information communication apparatus has a television tuner function. Because a television tuner circuit, which receives and converts a TV signal to digital data, is required in order to enjoy audio and visual of a TV program. On the other hand, an average user of a mobile information communication apparatus usually possesses a TV receiver or “AV-PC” with a larger screen besides a mobile information communication apparatus, since display means belonging to the mobile apparatus is poor both in size and in image quality. Thus, the user is forced to possess both television tuner circuit in a mobile information communication apparatus and that of a TV receiver or “AV-PC” and that results in low operating rate of one television tuner at least.
In the case of a digital terrestrial broadcast, simple overlapping investment seams not to occur because a television tuner of a TV receiver and that of a mobile information communication apparatus are different in specification, since segments (high-vision broadcast) or 4 segments (normal broadcast) out of 13 segments comprising one channel are assigned to a normal TV receiver and 1 segment is assigned to a mobile information communication apparatus. As a result of development of electrical and information technology, however, it is probable that a tuner receiving 12 segments or 4 segment broadcast, which is intended to be received by a normal TV receiver at present, will be installed in a mobile information communication apparatus, and, if then, similar problem of “irrational overlapping investment” and “inefficient resource use” will occurs in the field of a digital television tuner, which is expensive on the current level of technology.
Because of such a situation, it is recognized as an issue that, by using a mobile information communication apparatus not a PC, a long e-mail, a web page for PC, a highly entertaining game and a moving image of TV program is displayed in a larger screen, keeping the size of its own attached display means the same as present not to harm its portability. Especially, as for a web page for PC, it is an issue that a screen image similar to that of PC is displayed, and as for a TV program, it is an issue that an intrinsic image of a TV broadcast is displayed in full-screen.
In order to solve such an issue, some technologies are disclosed to display an image in a larger-screen external display device than a display means belonging to a mobile information communication apparatus by connecting the larger-screen external display device to the mobile information communication apparatus.
Hereinafter, “an external display device with a larger screen than a display means belonging to a mobile information communication apparatus” is referred as “an larger-screen external display device”.
And such technologies are categorized into the following three types:    1st type: A mobile information communication apparatus and a larger-screen external display device are connected with each other via some connection unit;    2nd type: A mobile information communication apparatus and a larger-screen external display device are directly connected, and the larger-screen external display device is an image display device with a special function to make various processes on display data, which is received from the mobile information communication apparatus;    3rd type: A mobile information communication apparatus and a larger-screen external display device are directly connected, and a commonly used display device such as a TV monitor, which does not have any special means except interface means with the mobile information communication apparatus, is used as the larger-screen external display device.
The 1st types of technologies are disclosed for example in Patent Document 1, Patent Document 2, Patent Document 3 and Patent Document 4.
The technologies disclosed in these patent documents do not require to use a PC separately from a mobile information communication apparatus but some connection unit with a display data processing means such as a processor (in Patent Document 1), a CPU (in Patent Document 2), a reading control circuit (in Patent Document 3) and a display control circuit (Patent Document 4) instead. Such a display data processing means has a function only to display characters and images on the screen and is not versatile as a CPU and other processors or OS and other software of PC. Thus, it is possible that a cost of a connection unit with a display data processing means is cheaper than that of a PC, and it is more economically acceptable to possess such a connection unit than to possess a PC in addition to a mobile information communication apparatus.
Even though, a user still possesses each display data processing means with almost the same display data processing function to display images and characters both in the mobile information communication apparatus and in the connection unit except that the size of screens, on which images are displayed, are different. In this case, therefore, similar problem of “irrational overlapping investment” and “inefficient resource use” will also occur as in the case to use a PC in addition to a mobile information communication apparatus. And it is realistically possible that purchases cost of a connection unit will be the same as that of a PC or higher than that of PC.
On the other hand, the 2nd types of technologies are disclosed for example in Patent Document 5, Patent Document 6, Patent Document 7, Patent Document 8 and Patent Document 9.
This type of technologies does not require a PC or a connection approximately equivalent to a PC. However, it is required that an image display device with a display data processing means such as a control system (a micro computer) (in Patent Document 5), a control part 5 (in Patent Document 6, which is different from a control part 10 in wireless telephone), a high definition convert part and a display processing part (in Patent Document 7), an expanding circuit and a display circuit (in Patent Document 8), or a CPU (in Patent Document 9), since, in this case, a commonly used display device such as TV monitor cannot be used as it stands.
The a technology categorized in the 3rd type is also disclosed in Patent Document 6, and in the technology control part 10 in a wireless telephone has an additional display data processing function. Thus, a control part 15 in a larger-screen external display device (a mobile display) only sends display data inputted from connector terminal 13 to a liquid crystal display panel belonging to a mobile display, so that it does not have any display data processing function. This technology will be discussed in the paragraph where the 3rd type of technology is discussed.
Since, in the 2nd types of technologies, each display data processing means with almost the same function is equipped both in a mobile information communication apparatus and in a larger-screen external display device as described above, the problem of “irrational overlapping investment” and “inefficient resource use” also occurs. And since purchases cost of an image display device with such a display data processing means will be surely more expensive than that of a commonly used CRT (Cathode Ray Tube) display device and a normal liquid crystal display device, a similar irrational economic burden as occurs in when a PC is additionally used or the 1st type of technology is adopted, which should be avoided, also occurs.
On the other hand, the 3rd type of technology does not use a connection unit or a special image processor and is comprised only of a mobile information communication apparatus and a commonly used larger-screen external display device without any special functions. Thus, in general, the 3rd type of technology is supposed to be more unlikely to yield the problem of “irrational overlapping investment” and “inefficient resource use” than the 1st and the 2nd type of technology.
A mobile telephone unit with so-called “TV output function” or “AV output function” is commercially available, which is categorized in the 3rd type of technology. In such a mobile telephone unit, the mobile telephone unit is connected to a TV monitor via special cable of which telephone side terminal is a special connecting terminal and of which monitor side terminal is a video terminal and it is possible to display a still image and a moving image, which are taken by using its own attached digital camera function, and certain games on a TV monitor, of which screen is larger than that of a display means belonging to the mobile telephone unit. In this case, however, a resolution of an image displayed on a TV monitor is the same as screen's resolution of a display means belonging to a mobile telephone unit (QVGA at largest) so that a small image is displayed in the center of TV monitor or expanded image with poor quality is displayed in full screen.
At present, only still images and moving images, which are taken by a mobile telephone unit itself, or certain games are displayed on a TV monitor. Even though, however, such a mobile telephone unit has “a full browser function” or “a PC site view function” and a browsed web page for PC is displayed on a TV monitor, the same screen image as displayed on its own attached display means should be only enlarged without increasing image resolution. Therefore, a display in the same layout as that is realized on a PC screen and is originally intended by a web page creator should not be realized on a TV monitor. Moreover, even though, such a mobile telephone unit has a television tuner function and a received image is outputted to a TV monitor, an intrinsic image of a TV broadcast should not be displayed on a TV monitor.
Therefore, in order to solve the above issue, it is not sufficient for a mobile information communication apparatus to have such a function to enlarge an image, which is displayed on its own attached screen, and to display it on a larger-screen external display device as a mobile telephone unit with “TV output function” or “AV output function”. It is necessary to provide a mobile information communication apparatus with a function that an image with a higher resolution than a screen's resolution of its own attached display means can be displayed on a larger-screen external display device.
If such a mobile information communication apparatus is provided, a whole image with an intrinsic resolution can be displayed on an external display with a larger screen, even if only a part image or a whole image with poor quality, of which pixels are thinned out, can be displayed on its own attached display panel. Especially, if a mobile information communication apparatus has a function to display an image of which horizontal pixels is larger than the horizontal resolution of its own display screen, number of characters can be increased which can be displayed in a line. Herewith, text does not extend in many lines nor is necessary to be rolled down frequently, even when the mobile information communication apparatus receives long e-mail. By synthesizing these effects, a web page for PC is displayed on a larger-screen external display device in the same layout as is realized on a screen of a PC.
The 3rd types of technologies, which are intended to solve issues similar to the above issue, are disclosed, for example, in Patent Document 6, Patent Document 10, Patent Document 11, Patent Document 12 and Patent Document 13.
In Patent Document 10 and Patent Document 11, it is disclosed that a TV receiver including a digital TV receiver is selected as a larger-screen external display device, and a video circuit and a video terminal, an interface circuit and a connector, or a transmitter circuit and an antenna (these all in Patent Document 10), or a neighborhood communication means (part) (in Patent Document 11) are provided as interface means between a mobile information communication apparatus and a larger-screen external display device. In these documents, however, a mechanism is not described at all how to display screen images with different information amount on display (display part) of a mobile telephone unit and on an external display with a larger screen, which have different screen sizes.
In Patent Document 11, in fact, it is disclosed that a control part 17 controls both a display part 11 and a neighborhood communication 18, but it is not disclosed at all by what mechanism said display part 17 should have in order that a screen image with less information amount is displayed on displayed part 17 and a screen image with more information amount is displayed on a digital TV 2, which sends and receives data between neighborhood communication 18. In Patent Document 10, on the other hand, it is suggested that a display actuating part controls a signal output to a (digital) TV receiver, but it is not disclosed at all how an image is displayed on a display means belonging to a mobile telephone unit.
On the other hand, in Patent Document 6 and Patent Document 12, it is disclosed that a mobile display (in Patent Document 6) or a CRT display (in Patent Document 12) is selected as a larger-screen external display device and an external interface (in Patent Document 6) or a monitor terminal (Patent Document 12) is provided as interface means. And also a mechanism is disclosed how to display a screen image with less information amount on a display part of a wireless telephone unit (in Patent Document 6) or a personal liquid crystal display panel of a mobile telephone unit (Patent Document 12) and to display a screen image with more information amount on a larger-screen external display device.
At first, in Patent Document 6, a control part 10 of a wireless telephone unit has a function to output display data of an image both to a display part 2 of a wireless telephone unit and to an external interface 3, and also has functions as enlargement means and enlargement control means and functions as linefeed means and linefeed control means. And it is described that an image, of which size is larger than that of image displayed in the display part 2 belonging to the wireless telephone unit, is displayed on a liquid crystal display 12 belonging to the mobile display and it is possible to increase number of characters displayed in one line.
However, additional functions disclosed in the document are restricted to functions related to image enlargement, which are already realized in a mobile telephone unit with “TV output function” or “AV output function”, and to functions related to a display of characters. It is impossible that solely by the technologies disclosed in Patent Document 6 that, for example, a whole image with an intrinsic resolution is displayed on an external display with a larger screen, if only a part image or a whole image with poor quality, of which pixels are thinned out, can be displayed on its own attached display panel. Therefore, the technology disclosed in Patent Document 6 cannot solve the issue completely to provide a mobile information communication apparatus with a function that an image with a higher resolution than a screen's resolution of its own attached display means can be displayed on a larger-screen external display device.
On the other hand, in Patent Document 12, it is disclosed that a display control circuit 21 has a function to send inputted display data separately both to a personal liquid crystal display panel 23 belonging to a mobile telephone unit and to a monitor terminal 25 connected to a CRT display under the control of a CPU 11. It is explained that, even if the amount of display data of image is too much to display the contents of display data on the personal liquid crystal display panel 23, all data is displayed on the CRT display without any deficiency according to this function.
This technology can seemingly solve the above issue to display a web page for PC on a larger-screen external display device in a similar image as that realized in a PC. Patent Document 12, however, has the following two problems.
Firstly, the mechanism for the display control circuit 21 to send display data separately both to the personal liquid crystal display panel 23 and to the monitor terminal 25 is not unknown. In Patent Document 12, there is a description saying “when display contents correspond to . . . ” or “when the destination of display data indicates . . . ”, but it is not disclosed at all by what mechanism the “correspondence” is judged or by what mechanism the “indication” is realized.
Secondly, it is not unworn what kind of image is displayed on the personal liquid crystal display panel 23 when display data corresponding to the CRT display 24 is inputted to the display control circuit 21 under the situation that the CRT display is not connected to the monitor terminal 25 and the mobile telephone unit is solely used. If, in such a situation, no image is displayed on the personal liquid crystal display panel 23, user convenience is reduced. If a part image is displayed on the personal liquid crystal display panel 2 and a whole image can be seen by screen scrolling, such mechanism to realize this is not disclosed at all.
Therefore, the technology disclosed in Patent Document 12 does not also solve the issue to provide a mobile information communication apparatus with a function to display an image with a higher resolution than a screen's resolution of its own attached display means on a larger-screen external display device.
Lastly, Patent Document 13 discloses the technology to provide a processor having a wide variety of functions in a telephone to display an image on a screen of a TV receiver that is a larger-screen external display device. The technology enables to display various information, including HTML contents comprising a web page for PC, on a large screen of a TV receiver and also is supposed to enable a web page for PC to be displayed on a larger-screen external display device in a similar image as that realized in a PC.
However, the processor installed in the telephone unit is high class enough to include various processors, such as a CPU 50a, a graphic processor, a sound processor and a DMA processor, and input/output ports. Moreover, the processor sole takes a role of image processing and, in contrast, a CPU 36 belonging to the telephone unit just takes a role of delivery of key input data and HTML contents data according to a request of the CPU 50a belonging to the processor. Thus, as for image processing, the situation is the same as the case that a mobile telephone unit and a PC are used at the same time and a wireless communication means of a mobile telephone unit is utilized only to connect to network.
Therefore, the technology disclosed in Patent Document 13 is formally categorized into the 3rd type, but there is no significant difference between 1st type and 2nd type of technology on the viewpoint of “irrational overlapping investment” and “inefficient resource use”.    Patent Document 1: Japanese laid-open patent publication No. 2001-189808    Patent Document 2: Japanese laid-open patent publication No. 2001-251449    Patent Document 3: Japanese laid-open patent publication No. 2001-352373    Patent Document 4: Japanese laid-open patent publication No. 2003-244289    Patent Document 5: Japanese laid-open patent publication No. 9-237145    Patent Document 6: Japanese laid-open patent publication No. 2001-268180    Patent Document 7: Japanese laid-open patent publication No. 2002-116843    Patent Document 8: Japanese laid-open patent publication No. 2002-164969    Patent Document 9: Japanese laid-open patent publication No. 2003-98974    Patent Document 10: Japanese laid-open patent publication No. 2001-345894    Patent Document 11: Japanese laid-open patent publication No. 2002-101457    Patent Document 12: Japanese laid-open patent publication No. 2001-197167    Patent Document 13: Japanese laid-open patent publication No. 2002-314646